1. Field of the Invention
The present invention relates to means for securing heat sinks in apparatus such as computers, and particularly to a clip assembly for attaching a heat sink to a computer electronic package.
2. Related Art
Developments in integrated circuits have resulted in greater circuit density and complexity, thus increasing heat generated by operation of such integrated circuits within an electronic package. Heat sinks are often attached on the electronic packages to efficiently remove the heat.
Nowadays, a resilient clip is popularly used to attach a heat sink on an electronic package such as a central processing unit (CPU). The clip engages with a socket of the CPU. However, the CPU bears an entire weight of the heat sink. If a large, heavy heat sink is employed, it is difficult for the assembly to pass a standard vibration test. Furthermore, when a large heat sink is attached to the CPU, it is difficult to ensure that the retaining forces applied by the clip are uniform. If the retaining forces are not uniform, the heat sink is unlikely to have uniform thermal contact with the corresponding surface of the CPU. In such case, the efficiency of heat dissipation is reduced.
Another means for attaching a heat sink on a CPU comprises four through holes defined in four corners of the heat sink, and four threaded holes defined in a motherboard. Screws are extended through the through holes of the heat sink and engaged in the threaded holes of the motherboard, thereby attaching the heat sink to the CPU. However, the heat sink is rigidly connected to the CPU. It is difficult to ensure that the heat sink applies uniform pressure on the CPU, thus tending to reduce the efficiency of heat dissipation. Furthermore, the rigid connection is prone to deform the motherboard.
Therefore, an improved means for securing a heat sink which overcomes the above-mentioned problems is desired.